scholarly journals Microstructure and Mechanical Properties of Ultrafine Quaternary Al-Cu-Si-Mg Eutectic Alloy

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Qing Cai ◽  
Brian Cantor ◽  
Vivian S. Tong ◽  
Feng Wang ◽  
Chamini L. Mendis ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Eutectic Alloy ◽  
Cast Alloy ◽  
Eutectic Reaction ◽  
High Strength ◽  
Eutectic Structure ◽  
Eutectic Cell ◽  
Orientation Relationships ◽  
Arc Melting ◽  
Alloy Microstructure

The microstructure evolution and mechanical properties of quaternary Al-Cu-Si-Mg eutectic alloy prepared via arc melting and suction casting were studied. This alloy exhibits a single endothermic DSC peak with a melting temperature of 509 °C upon heating, suggesting a eutectic reaction. The cast alloy microstructure consisted of four phases, α-Al, Al2Cu (), Si and Al4Cu2Mg8Si7 (Q), in the eutectic cells and also in the nano-scale anomalous eutectic in the intercellular regions. The eutectic cells show different morphologies in different parts of the sample. Well-defined orientation relationships between the α-Al, Al2Cu, and Q phases were found in the eutectic cell centres, while decoupled growth of Q phase occurred at the cell boundaries. The bimodal microstructure exhibits excellent compressive mechanical properties, including a yield strength of 835 ± 35 MPa, a fracture strength of ~1 GPa and a compressive fracture strain of 4.7 ± 1.1%. The high strength is attributed to a combination of a refined eutectic structure and strengthening from multiple hard phases.

Effect of Excess Mg on the Microstructure and Mechanical Properties of Al-Mg2Si High Pressure Die Casting Alloys

2013 ◽  
Vol 765 ◽  
pp. 64-68 ◽  
Author(s):  
Feng Yan ◽  
Shou Xun Ji ◽  
Zhong Yun Fan
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Mechanical Performance ◽  
Eutectic Reaction ◽  
Die Casting ◽  
High Strength ◽  
Primary Phase ◽  
High Pressure Die Casting ◽  
Excess Mg ◽  
Pressure Die Casting

In this work we found that the addition of excess Mg can significantly improve the mechanical properties of pseudo-binary Al-Mg2Si alloys after high pressure die casting (HPDC). Al-8Mg2Si-6Mg alloy offered an excellent combination of high strength and reasonable ductility. Excess Mg lowers the Mg2Si content in the eutectic reaction and promotes the formation of Mg2Si as the primary phase, and this is believed to be the origin of improved mechanical performance.

Microstructure and Mechanical Properties of a Nb-Microalloyed Medium Carbon Steel Treated by Quenching-Partitioning Process

2012 ◽  
Vol 531-532 ◽  
pp. 596-599
Author(s):  
Kai Zhang ◽  
Shang Wen Lu ◽  
Yao Hui Ou ◽  
Xiao Dong Wang ◽  
Ning Zhong
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electron Microscope ◽  
Carbon Steel ◽  
Retained Austenite ◽  
High Strength ◽  
Medium Carbon Steel ◽  
Orientation Relationships ◽  
Medium Carbon ◽  
Microstructure And Mechanical Properties

The recently developed “quenching and partitioning” heat treatment and “quenching-partitioning-tempering” heat treatment are novel processing technologies, which are designed for achieving advanced high strength steels (AHSS) with combination of high strength and adequate ductility. In present study, a medium carbon steel containing Nb was subjected to the Q-P-T process, and both the microstructure and mechanical properties was studied. The experimental results show that the Nb-microalloyed steel demonstrates high tensile strength and relatively high elongation. The microstructure of the steel was investigated in terms of scanning electron microscope and transmission electron microscope, and the results indicate that the Q-P-T steel consist of fine martensite laths with dispersive carbide precipitates and the film-like interlath retained austenite. The orientation relationships between martensite and retained austenite is as well-known Kurdjurmov-Sachs relationship and Nishiyama-Wasserman relationship.

Effects of Hot Extrusion on Microstructure, Texture and Mechanical Properties of Mg-5Li-3Al-2Zn Alloy

2013 ◽  
Vol 773-774 ◽  
pp. 218-225
Author(s):  
Le Gan Hou ◽  
Rui Zhi Wu ◽  
Ji Qing Li ◽  
Jing Huai Zhang ◽  
Mi Lin Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Grain Refinement ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Eutectic Structure ◽  
Basal Texture ◽  
Lamellar Eutectic ◽  
Lamellar Eutectic Structure

This work mainly studied the effects of hot extrusion on microstructure, texture and mechanical properties of Mg-5Li-3Al-2Zn alloy. The results show that the microstructures of as-cast and as-extruded alloys both consist of α-Mg matrix and lamellar eutectic structure (α-Mg and AlLi phases). During the hot extrusion, the large eutectic structure of as-cast alloy was crushed into small eutectic structure and the grains were effectively refined. A {0002} basal texture was formed after hot extrusion. The as-extruded alloy exhibits remarkably improved tensile properties, which is mainly attributed to the grain refinement and the formation of texture.

Microstructure Characterization and Mechanical Properties of a Zn and Rare Earth Modified Mg Alloy

2015 ◽  
Vol 727-728 ◽  
pp. 111-114 ◽  
Author(s):  
Li Yuan Sheng ◽  
Fang Yang ◽  
Ting Fei Xi
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Eutectic Structure ◽  
Crystal Defects ◽  
Treatment Results ◽  
Nanoscale Particles ◽  
Residual Phase ◽  
Heat Treated ◽  
The Matrix

In the present paper, the Mg-Zn-Y-Nd alloy is fabricated by as casting and hot extrusion. Microstructure and mechanical properties of the as-cast, heat treated and hot extruded alloys are investigated. The results exhibit that Mg24Y5 phase with eutectic structure forms in the as-cast alloy, which has an orientation relationship with matrix of . The precipitating phase separates the matrix semi-continuously. The heat treatment results in most precipitates solid soluted into matrix, but there are still some nanoscale particles and residual phase along grain boundary. The hot extrusion refines the microstructure and leads to the formation of stacking faults in the matrix. Compared with the as-cast and heat treated alloy, the hot extruded alloy obtain great improvement in mechanical properties, which should be attributed to the grain refinement, solid solution and fomation of crystal defects

scholarly journals Anisotropic in Situ Metal Matrix Composite Reinforced with VC Carbide Fibres

2015 ◽  
Vol 15 (1) ◽  
pp. 21-24 ◽  
Author(s):  
M. Kawalec ◽  
M. Górny ◽  
G. Sikora
Keyword(s):  
Directional Solidification ◽  
Eutectic Reaction ◽  
High Strength ◽  
Initial State ◽  
Technical Literature ◽  
In Situ Composites ◽  
Alloy Microstructure ◽  
Two Phases ◽  
Primary Carbides

Abstract A eutectic reaction is a basic liquid-solid transformation, which can be used in the fabrication of high-strength in situ composites. In this study an attempt was made to ensure directional solidification of Fe-C-V alloy with hypereutectic microstructure. In this alloy, the crystallisation of regular fibrous eutectic and primary carbides with the shape of non-faceted dendrites takes place. According to the data given in technical literature, this type of eutectic is suitable for the fabrication of in-situ composites, owing to the fact that a flat solidification front is formed accompanied by the presence of two phases, where one of the phases can crystallise in the form of elongated fibres. In the present study an attempt was also made to produce directionally solidifying vanadium eutectic using an apparatus with a very high temperature gradient amounting to 380 W/cm at a rate of 3 mm/h. Alloy microstructure was examined in both the initial state and after directional solidification. It was demonstrated that the resulting microstructure is of a non-homogeneous character, and the process of directional solidification leads to an oriented arrangement of both the eutectic fibres and primary carbides.

Synthesis, Microstructure, and Mechanical Properties of FeCo-VC Composites

2006 ◽  
Vol 980 ◽  
Author(s):  
Hongbin Bei ◽  
E. P. George
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Eutectic Structure ◽  
Directionally Solidified ◽  
Quaternary Alloys ◽  
The Matrix ◽  
Solid Solution Matrix ◽  
Solution Matrix

AbstractFe-Co-V-C quaternary alloys were drop cast and directionally solidified to obtain an in situ composite. It is found that the fully eutectic structure occurs at a composition of Fe - 40.5Co -10.4V- 8.6C (at. %) in a drop-cast alloy. Directional solidification of this composition in a high-temperature optical floating zone furnace produces a well-aligned microstructure, consisting of sub-micron VC fibers (~19% by volume) embedded in a FeCo-5V solid solution matrix containing ~ 1% C. The temperature dependencies of mechanical properties of this composite were examined by tensile tests and the composite was found to have higher yield strength and lower ductility than the matrix.

scholarly journals Hopeful high-strength casting alloys based on Al―Mg―Ge(Si) ternary systems

2020 ◽  
Vol 2020 (01) ◽  
pp. 55-66
Author(s):  
N. P. Korzhova ◽  
◽  
T. M. Legka ◽  
Y. V. Milman ◽  
K. E. Grinkevich ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Cast Alloy ◽  
High Strength ◽  
Ternary Systems ◽  
Eutectic Type ◽  
Eutectic Alloys ◽  
Binary Eutectic ◽  
Casting Aluminum ◽  
Multicomponent Eutectic

The relative analysis of phase equilibria in the Al-corner of the ternary phase diagrams of Al―Mg―Ge(Si) systems is carried out. Both systems are characterized by the presence of a quasi-binary cross-section of the eutectic type, which is shifted towards Mg-enriched alloys, and sufficiently width range existence of the univariant eutectic transformation L-Al + Mg2Ge(Si). The melting point of quasi-binary eutectic (-Al + Mg2Ge) in the Al―Mg–Ge system and (-Al + Mg2Si) in the Al―Mg―Si is 629 °С and 597 °С, respectively, and the content of the strengthening phase ((Mg2Ge or Mg2Si) in eutectics is 7% (vol.) и 13% (vol.). The properties of non-alloyed alloys with different volume content of eutectic are investigated and the basic compositions of alloys with the optimal strength/ductility ratio for subsequent doping are selected as well. Taking into account the coordinates of the corresponding eutectic transformations, the doping system with the participation of Zn, Cu and other elements is determined. The heat treatment regimes for multicomponent eutectic alloys were selected, to ensure precipitation of Zn(Cu)-nanoparticles that strengthen matrix solid solution. It was shown that according to the level of mechanical properties, these alloys belong to high-strength alloys with property ranges: -Al + Mg2Ge) ― В = 470―590 МPа, 0,2 = 350―520 МPа, = 8,0―15,5%; -Al + Mg2Si) ― В = 400―560 МPа, 0,2 = = 430―520 МPа, = 2,3–-4,5%. Using a complex U-like Nechenji―Kuptsov test, casting properties were determined and it was shown that the fluidity of (-Al + Mg2Si) alloy was 1,3 times higher than that of the AK7ch cast alloy. In terms of the combination of mechanical and casting properties, the new multicomponent eutectic alloys based on the Al―Mg―Ge(Si) ternary systems are superior to the best modern industrial casting aluminum alloys. Keywords: casting aluminum alloys, ternary Al―Mg―Ge(Si) systems, eutectic alloys, alloying, microstructure, mechanical properties, fluidity.

Effect of Ni Coating on Hydrogenation Kinetics in Pure Mg and Mg-Mg2Ni Eutectic Alloy

2007 ◽  
Vol 26-28 ◽  
pp. 865-868 ◽  
Author(s):  
Masaaki Kusumoto ◽  
Hideyuki Saitoh
Keyword(s):  
Surface Modification ◽  
Eutectic Alloy ◽  
Catalytic Effect ◽  
Cast Alloy ◽  
Eutectic Structure ◽  
Hybridization Method ◽  
Alloy Specimen ◽  
Heat Treated ◽  
Hydrogenation Kinetics ◽  
Kinetics Of

We have applied hybridization method to the surface modification by Ni coating on powder specimens of pure Mg and Mg-Mg2Ni eutectic alloy, and investigated the effect of the Ni coating on the hydrogenation kinetics in them. The hydrogenation kinetics at 350 degree C is greatly increased by the Ni coating for both the pure Mg and Mg-Mg2Ni eutectic alloy specimens. Thus, it is confirmed that the surface modification by the hybridization method is considerably effective to improve the hydrogenation kinetics in them. This improvement is thought to be a catalytic effect of the coated Ni. The hydrogenation kinetics of the Mg-Mg2Ni alloy specimen heat-treated at 470 degree C has increased compared with that of the as-cast alloy specimen. It is also confirmed that hydrogenation kinetics improves by the heat treatment to grow the eutectic structure consisted of Mg2Ni phase and Mg phase.

Effect of Sn on microstructure and mechanical properties of Ti-Fe-(Sn) ultrafine eutectic composites

2010 ◽  
Vol 25 (5) ◽  
pp. 943-956 ◽  
Author(s):  
Jayanta Das ◽  
Ralf Theissmann ◽  
Wolfgang Löser ◽  
Jurgen Eckert
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
High Strength ◽  
Lattice Parameter ◽  
Eutectic Alloys ◽  
Two Phase ◽  
Arc Melting ◽  
Structural Fluctuations ◽  
Strength And Plasticity ◽  
Micrometer Size

High strength (Ti0.705Fe0.295)100-xSnx (0 ≤ x ≤ 6) composites have been prepared through arc melting and cold crucible casting. The microstructure consists of two phase ultrafine eutectic comprised of FeTi and β-Ti phases. The effect of Sn addition to the Ti70.5Fe29.5 eutectic is assessed in terms of microstructure variations such as eutectic spacing, morphology, cell size, lattice parameter of the phases, and the resulting mechanical properties in terms of strength and plasticity under compression. The mechanical properties (maximum strength 1939 MPa, fracture strain 13.5%) of the ternary Ti-Fe-Sn (2 ≤ x ≤ 6) are considerably improved compared to the Ti70.5Fe29.5 binary alloy (1733 MPa, 3.4%). The change in the morphology of the eutectic, the microstructure refinement, structural fluctuations, and supersaturation in the β-Ti phase, and the elastic properties of nanophases are crucial factors for improving the plastic deformability of the ultrafine eutectic alloys without presence of any additional micrometer-size toughening phase.

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